The Maryland Court of Appeals opinion finds that the Department’s municipal stormwater permits for Baltimore City and Anne Arundel, Baltimore, Montgomery and Prince George’s counties comply with the federal Clean Water Act. Previous lower court rulings had upheld the legality of these Municipal Separate Storm Sewer System (MS4) permits for other Maryland counties.

The Court of Appeals opinion supports the Department’s approach to reducing polluted stormwater: each jurisdiction is required to treat or reduce 20 percent of its impervious surface area during the course of the permit and take other specified actions. Reducing the amount of hard, impervious surfaces allows the ground to absorb polluted stormwater that would otherwise be channeled into storm drains and, eventually, waterways.

Polluted stormwater runoff is a significant source of the sediment and nutrient pollution that threatens the health of the Chesapeake Bay and its tributaries, and reducing this pollution source is a crucial part of Maryland’s federally approved Bay restoration plan. Stormwater runoff can also carry other pollutants into waterways.

“The Court of Appeals ruling is a big win for the Chesapeake Bay and local streams and rivers,” Maryland Environment Secretary Ben Grumbles said. “The ruling supports our approach of combining accountability with flexibility to help local governments find practical solutions to reducing polluted stormwater runoff.”

U.S. Environmental Protection Agency’s (EPA) National Pollutant Discharge Elimination System (NPDES) stormwater regulations require large urban jurisdictions to control pollution in stormwater to the “maximum extent practicable.” In Maryland, Baltimore City and Anne Arundel, Baltimore, Carroll, Charles, Frederick, Harford, Howard, Montgomery and Prince George’s counties, along with the Maryland State Highway Administration, are issued individual stormwater permits. Although individual permits are not issued for smaller jurisdictions, these jurisdictions are also required under NPDES regulations to implement measures to reduce polluted stormwater runoff.

Maryland began issuing stormwater permits to the state’s large jurisdictions in 1993, and permits are updated every five years.The most recent updates to the permits for Maryland’s large jurisdictions were issued in 2013 and 2014 following a public participation process.Permit requirements include: implementing comprehensive stormwater management programs for addressing runoff from new and redevelopment projects; restoring urban areas where there is currently little or no stormwater management; and working toward meeting stormwater waste load allocations for local water resources and the Chesapeake Bay. Also included in the permit are conditions that require counties to possess the necessary legal authority to control stormwater discharges, map their storm drain systems, monitor urban runoff and eliminate illicit discharges to storm drain systems.

Additional information on Maryland’s NPDES Municipal Storm Sewer System permits is available on the Department’s website at http://bit.ly/MDMS4permits.